1. Field of the Invention
The invention relates to an apparatus for harvesting seed bearing cones from coniferous trees for the purpose of growing seedlings for re-forestation and other commerical purposes.
2. Prior Art
Manual methods of collecting cones have been used for many years and commonly these resulted in severe damage to, or total loss of, the tree. Seed bearing cones tend to grow adjacent the upper portion of the tree, and in the past the tree was felled to enable collection of the cones, or at least topped so that the top of the tree fell to the ground to enable the cones to be collected manually therefrom.
Apparatus for retrieving cones from trees using cone collecting apparatus suspended from helicopters have been tried recently but, to the inventor's knowledge, have not been particularly successful. Flying helicopters at low levels over forests involves high risks to the pilot and helicopter, which risks are further compouned by flying in mountainous terrain where air currents are notoriously unpredictable. Some cone collecting apparatus require that the helicopter approaches the tree in a particular direction, which involves skillful flying and further limits use of the apparatus to certain wind conditions. Other apparatus are lowered vertically down the tree and have devices adapted to engage the tree when the apparatus is pulled upwardly. These devices tend to grab onto the tree, and sometimes jam on the tree which requires the helicopter pilot to jetison the apparatus to reduce risk to himself and the helicopter. Other apparatus also enclose the tree, but use fixed radially outwardly extending rakes or knives adapted to cut branches or pull cones from the trees.
When successful, these apparatus permit branches containing cones, or cones with a small amount of foliage, to be stripped from the tree, and collected in a holding portion of the apparatus. The helicopter then flies to an unloading station where the cones or branches containing the cones are unloaded by an operator on the ground. The unloading commonly involves the helicopter hovering over the ground and suspending the apparatus therefrom whilst it is being unloaded, or alternatively the helicopter must land for the time required for manually unloading. Because unloading might take perhaps between 5 and 15 minutes to release jammed branches and cones, "turn-around" time of the helicopter between trips to the trees is relatively long and thus considerably increases the cost of the operation in view of the high cost of operating helicopters.